Abstract:

Objective To explore the effect of cornus officinalis glycosides on proliferation and apoptosis of chondrocytes in human osteoarthritis exposed to cadmium based on microRNA-655（miR-655）/Mothers against decapentaplegic homolog 7（SMAD7）/Interleukin-1β（IL-1β） signaling pathway. Methods The cell experiments were conducted in the molecular biology laboratory of Qinhuangdao First Hospital from January to October 2024. The human osteoarthritis chondrocytes were divided into control group，cadmium exposure group（10 μmol/L），cornus officinalis glycosides（10 μmol/L） group，and cornus officinalis glycosides（50 μmol/L） group，and all groups were cultured for 72 hours. After the experiment，CCK-8 was used to measure cell proliferation，crystal violet staining was used to measure cell monoclonal formation，flow cytometry was used to measure cell apoptosis and cycle levels，and real-time fluorescence reverse transcription and Western blotting were used to measure cell miR-655，SMAD7，IL-1β levels，and cellular tumor necrosis factor-α（TNF-α） and interleukin-12（IL-12） levels were measured by ELISA method. Results Compared with the control group，the cell proliferation level of human osteoarthritis chondrocytes（hOACs） in the cadmium exposure group [survival rate：[（34.56±1.41）% vs 92.74±3.32）%]，the number of cell monoclones formed（152.32±10.55 vs 605.65±48.65），SMAD7 mRNA（0.97±0.03 vs 4.26±0.19） and protein expression（0.27±0.03 vs 1.29±0.12） were significantly reduced（all P<0.05），while apoptosis rate[（2.95±0.12）% vs （12.92±0.85）%]，G2/M phase ratio[（44.27±4.45）% vs （10.16±1.37）%]，miR-655 mRNA（5.24±0.23 vs 0.99±0.04），IL-1β mRNA（4.32±0.53 vs 0.63±0.07） and protein（1.10±0.12 vs 0.21±0.03），TNF-α（459.22±46.32 vs 67.52±5.66） and IL-12 protein expression（632.25±45.57 vs 89.44±4.26） were significantly increased（all P<0.05）. In the cornus officinalis glycosides（50 μmol/L）groups，the hOACs cell proliferation level[survival rate：（79.35±1.94）% vs （34.56±1.41）%]，the number of cell monoclonal formation（498.54±31.22 vs 152.32±10.55） and SMAD7 mRNA（3.79±0.17 vs 0.97±0.03） and protein expression（0.99±0.09 vs 0.27±0.03） were significantly higher than those in the cadmium exposure group（all P<0.05）. The apoptosis rate[（10.99±0.65）% vs （2.95±0.12）%]，G2/M phase ratio[（13.59±2.64）% vs （44.27±4.45）%]，miR-655 mRNA（1.23±0.07 vs 5.24±0.23），IL-1β mRNA（0.85±0.10 vs 4.32±0.53） and protein（0.39±0.04 vs 1.10±0.12），TNF-α（105.25±10.22 vs 459.22±46.32） and IL-12 protein expression（159.67±23.65 vs 632.25±45.57） were significantly lower than those in the cadmium exposure group（all P<0.05）. The proliferation level[（79.35%±1.94）% vs（64.25±1.80）%]，the number of cell monoclonal formation（498.54±31.22 vs 254.12±20.12），SMAD7 mRNA（3.79±0.17 vs 1.21±0.04） and protein expression（0.99±0.09 vs 0.65±0.07） in cornus officinalis glycosides（50 μmol/L） group were significantly higher than those in the 10 μmol/L group（all P<0.05）. The apoptosis rate[（10.99±0.65）% vs （5.97±0.24）%]，G2/M phase ratio[（13.59±2.64）% vs （20.36±2.27）%]，miR-655 mRNA（1.23±0.07 vs 3.32±0.14），IL-1β mRNA（0.85±0.10 vs 2.74±0.20） and protein（0.39±0.04 vs 0.62±0.06），TNF-α（105.25±10.22 vs 254.21±35.21） and IL-12 protein expression（159.67±23.65 vs 322.02±29.54） in cornus officinalis glycosides（50 μmol/L） group were significantly lower than those in the 10 μmol/L group（all P<0.05）. Conclusion The cornus officinalis glycosides can promote the proliferation of cadmium-exposed human osteoarthritis chondrocytes，inhibit their apoptosis，and play a significant protective role in the damage of human osteoarthritis chondrocytes caused by cadmium exposure，it is related to the activation of the miR-655/SMAD7/IL-1β signaling pathway in inflammatory chondrocytes.

Key words: MicroRNA-655, Mothers against decapentaplegic homolog 7, Interleukin-1β, Cornus officinalis glycosides, Cadmium, Osteoarthritis, Chondrocytes